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Date: Fri, 23 Jun 2023 10:00:40 -0700
From: Jakub Kicinski <kuba@kernel.org>
To: David Howells <dhowells@redhat.com>
Cc: netdev@vger.kernel.org, Alexander Duyck <alexander.duyck@gmail.com>,
 "David S. Miller" <davem@davemloft.net>, Eric Dumazet
 <edumazet@google.com>, Paolo Abeni <pabeni@redhat.com>, Willem de Bruijn
 <willemdebruijn.kernel@gmail.com>, David Ahern <dsahern@kernel.org>,
 Matthew Wilcox <willy@infradead.org>, Jens Axboe <axboe@kernel.dk>,
 linux-mm@kvack.org, linux-kernel@vger.kernel.org, Ilya Dryomov
 <idryomov@gmail.com>, Xiubo Li <xiubli@redhat.com>, Jeff Layton
 <jlayton@kernel.org>, ceph-devel@vger.kernel.org
Subject: Re: [PATCH net-next v4 03/15] ceph: Use sendmsg(MSG_SPLICE_PAGES)
 rather than sendpage
Message-ID: <20230623100040.4ebbeeb2@kernel.org>
In-Reply-To: <20230623114425.2150536-4-dhowells@redhat.com>
References: <20230623114425.2150536-1-dhowells@redhat.com>
	<20230623114425.2150536-4-dhowells@redhat.com>
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On Fri, 23 Jun 2023 12:44:13 +0100 David Howells wrote:
> @@ -494,9 +466,12 @@ static int write_partial_message_data(struct ceph_connection *con)
>  
>  		page = ceph_msg_data_next(cursor, &page_offset, &length);
>  		if (length == cursor->total_resid)
> -			more = MSG_MORE;
> -		ret = ceph_tcp_sendpage(con->sock, page, page_offset, length,
> -					more);
> +			msghdr.msg_flags |= MSG_MORE;

Should the condition also be flipped here, like you did below?
(can be a follow up if so)

> @@ -534,9 +512,11 @@ static int write_partial_skip(struct ceph_connection *con)
>  		size_t size = min(con->v1.out_skip, (int)PAGE_SIZE);
>  
>  		if (size == con->v1.out_skip)
> -			more = MSG_MORE;
> -		ret = ceph_tcp_sendpage(con->sock, ceph_zero_page, 0, size,
> -					more);
> +			msghdr.msg_flags &= ~MSG_MORE;
> +		bvec_set_page(&bvec, ZERO_PAGE(0), size, 0);
> +		iov_iter_bvec(&msghdr.msg_iter, ITER_SOURCE, &bvec, 1, size);